Manufacture of isodibenzanthrones



Patented a. 11, 1927.

(UNITED STATES PATENT OFFICEA PAUL NA'WIASKY,'0F LunwmsnArzN-oN-rnn-nnmn, ANn orro nnAUNsn onr AND EDUABD HoLzArrEn, or EOCHST-ON-THE-MAIN, eaamNr AssreNons, BY MESNE ASSIGNMENTS, 'ro emssmr nmrurr'conromrIoN, or NEW Yoax, N. Y., A

CORPORATION 01 DELAWARE.

musician or-rsonrisnNzAN'rnnoNns.

No Drawing. Application illed November 28, 1985, Serial Io.'72 l,022, and in larch 5,- 1925i We have found that by treating .metrically substituted Bz 1.Bz 1- benzanthronyl sulfids having free 2-positions, with alkaline condensing agents, unsymmetrically V 5 substituted isodibenzanthrones are obtained which are remarkable by reason of their excellent tinctorial properties The said dibenzanthronyl sulfids may either possess a substituent in one benzan- 1 thronyl radicle while the other benzanthrothrone-mercaptane) corresponding to the formula is introduced at about 140 degrees centigrade into a melt prepared from 5 parts of caustic.

potash and 5 parts of ethyl alcohol; The 40 mixture is kept at the said temperature for an hour; it then poured into water while stirring and worked up in the usual manner.

The -Bz 2-methoxy-isodibenzanthrone corresponding to the formula dyes cotton from a warm sodium hydrosulfite vat which has a pure blue color, ve strong and clear blue-violet shades of exo lent fastness. The dyestufi dissolves inconcentr'ated sulfuric acid with a bluish green color.

7 Example 2. I 2 parts of fi-amino Ba-LBz-l benzan thronyl sulfid corresponding tothe formula which may be obtained for example by condensing 6 amino-Bz-l-chlorbenzanthrone with Bz-l-benzanthr'one mercaptane, are in- I troduced at a temperature of l40.degree s to degrees centigrade into amelt prepared from 10 partsof caustic potash and 10 parts of ethyl alcohol, and kept at this temperature for about an hour. The melt is worked up in the usual manner, and 6-amino-isodibenzanthrone corresponding to the formula is obtained with good yield; it dissolves in concentrated sulfuric acid bluish green and dyes cotton from a Warm sodium hydrosulfite vat strong violet shades.

We claim:

1. The process of manufacturing unsymmetrically substituted isodibenzanthrones which consists in treatingunsymmetrically substituted Bz-1.Bz-1'-benzanthronyl sulfids having free 2-positions with alkaline condensing agents.

2. The process of manufacturing unsymmetrically substituted isodibenzanthroniss which consists in treating unsymmetrically substituted Bz-1.Bz-1benzanthronyl sulfids havingfree 2- ositions with a mixture of caustic alkali an an alcohol at an elevated temperature. i

3. As a new article of manufacture, a vat colorin matter of the isodibenzanthrone series which is free of halo en and dyes from p a pure blue vat pure bluis violet shades and which may be obtained by heating Bz-2-- methoxy-Bz-LBz-l' benzanthronyl sulfid with a mixture of caustic alkali and alcohol. In testimony whereof we have hereunto set our hands.

- PAUL NAWIASKY.

OTTO BRAUNSDORF. EDUARD HOLZAPFEL. 

